Below are two excerpts from the "Service Efforts and Accomplishments: 2010" report.
“Part I Crimes” is a category of crimes established by the U. S. Department of Justice Federal Bureau of Investigation (FBI) that consists of murder, rape, robbery, aggravated assault, burglary, larceny, motor vehicle theft and arson. Part I Crimes compared to the population are known as the “Crime Index” or “Crime Rate.” (The Crime Rate is known as the Modified Crime Index when arson data is included.) Part I crimes are, by definition, felony crimes.
Below is a two year comparison of the “Modified Crime Index” for neighboring cities that are contiguous with the City of Edmonds.
“Part II Crimes” consist of all other crimes not included in the Part I Crimes category. Part II Crimes vary in definition due to differences in local laws. Some examples locally include simple assault, malicious mischief, vehicle prowl, fraud, forgery, narcotics violations and sex offenses (excluding forcible rape).
For more detail see the "Service Efforts and Accomplishments: 2010" report.